Transaxle

Abstract

A transaxle is provided, especially for small riding vehicles, such as lawn mowers. The transaxle is exceptionally shallow, with the gear shift lever entering the housing on about the same level as the rear axles. The transaxle has six forward speeds in a compact housing by virtue of a unique gear train arrangement in which shafts serve multiple functions. A driven bevel gear in the transaxle housing is also backed-up by a structurally-integral rib or flange in the housing. A unique bearing design provides effective lubrication for the output shafts or axles of the transaxle. A compact differential of the transaxle also rotates within a cavity without any axle.

We claim: 
     
       1. A transaxle comprising a housing, an input shaft rotatably carried by said housing, a shifting shaft rotatably carried by said housing, output shaft means carried by said housing, a driven gear on said input shaft, a first power-transmitting gear on said input shaft, two power-transmitting gears on said output shaft means meshing with said driven gear and said first power-transmitting gear, additional gear means for transmitting power from said driven gear to said output shaft means at a first range of speeds and from said first power-transmitting gear to said output shaft means at a second range of speeds, and shift means operable outside said housing for mechanically connecting said driven gear and said first power-transmitting gear to said input shaft, one at a time, said housing being in two parts with said input shaft, said shifting shaft, and said output shaft means carried by said parts at the meeting line, said input shaft, said shifting shaft, and said output shaft means being in a common plane with said output shaft means and said shifting shaft being on opposite sides of said input shaft. 
     
     
       2. A transaxle according to claim 1 characterized by said shift means comprising a shift dog mounted on said input shaft between said driven gear and said first power transmitting gear for slidable but non-rotatable movement with respect to said input shaft, a shift fork extending through said housing and engaging said shift dog, and lever means outside said housing for moving said shift fork. 
     
     
       3. A transaxle comprising an upper housing part, a lower housing part, an input shaft rotatably carried by said housing parts, a shifting shaft on one side of said shaft and rotatably carried by said housing parts, output shaft means on the other side of said input shaft and rotatably carried by said housing parts, a driven gear on said input shaft, at least one power-transmitting gear on said input shaft, at least two power-transmitting gears on said output shaft means, additional gear means on said input shaft and said shifting shaft for transmitting power to said output shaft means from said input shaft at a first plurality of different gear ratios from said driven gear and for transmitting power to said output shaft means from said input shaft at a second plurality of different gear ratios from said driven gear, said power-transmitting gear on said input shaft, and said power-transmitting gears on said output shaft means, and shift means for connecting said driven gear and said one power-transmitting gear on said input shaft to said input shaft, one at a time. 
     
     
       4. A transaxle comprising an upper housing part, a lower housing part, an input shaft rotatably carried by said housing parts, a shifting shaft on one side of said shaft and rotatably carried by said housing parts, output shaft means on the other side of said input shaft and rotatably carried by said housing parts, said output shaft means being two output shafts with a differential connecting the two shafts for transmitting power thereto, said housing parts having matching cavities forming a circular contour in the plane perpendicular to said two shafts, and said differential including a ring gear rotatably carried and supported by the boundaries of said cavities, said two output shafts extending into said cavities and each having a bevel gear affixed thereto, said ring gear having diametrically opposite channels, said channels being open ended and aligned with the axis of said ring gear, an axle received in said channels between the ends of said two output shafts, and bevel gears rotatably mounted on said axle and meshing with the bevel gears on said two output shafts, a driven gear on said input shaft, at least one power-transmitting gear on said input shaft, at least two power-transmitting gears on said output shaft means, additional gear means on said input shaft and said shifting shaft for transmitting power to said output shaft means from said input shaft at a first plurality of different gear ratios from said driven gear and for transmitting power to said output shaft means from said input shaft at a second plurality of different gear ratios from said driven gear, said power-transmitting gear on said input shaft, and said power-transmitting gears on said output shaft means, said differential being part of said additional gear means. 
     
     
       5. A transaxle according to claim 4 characterized by said additional gear means comprising two connected gears rotatably carried on said input shaft. 
     
     
       6. A transaxle according to claim 4 characterized by shift means operable outside of said upper housing part for shifting said transaxle between said first and said second plurality of different gear ratios.